Bottom Line:
This study investigates the observed incidence trends of the two types, the age, stage, and socioeconomic distribution of this increase and survival outcome.While outcome for type 1 cancer has improved, 1-year survival in type 2 cancer is unchanged from 73.1% in 1994 to 74.3%, P=0.089 and 5-year survival decreased from 55.1% to 40.9%, P=0.001.Urgent research is needed to investigate prevention strategies in type 1 and improve therapy in type 2 cancers.

Background: Endometrial cancer is the most common gynaecological cancer in the western world, the incidence increasing in the United Kingdom by over 40% since 1993. Two types of endometrial cancer exist - oestrogen-dependent type 1 with good prognosis and non-oestrogen-dependent type 2 with poor prognosis. The histopathological distribution of the increase in endometrial cancer is unknown. This study investigates the observed incidence trends of the two types, the age, stage, and socioeconomic distribution of this increase and survival outcome.

Methods: Data were analysed from 6867 women with endometrial cancer registered between 1994 and 2006, at a UK population-based cancer registry.

Results: Increased endometrial cancer incidence is confined to type 1 cancers with a significant increase in age standardised incidence rate (ASR) from 12.0 per 100,000 (confidence interval (CI) 10.7-13.2) in 1994 to 16.3 per 100,000 (CI 14.9-17.7), P<0.001 in 2006, while ASR of type 2 cancer changed from 2.5 per 100,000 (CI 2.0-3.1) in 1994 to 2.2 per 100,000 (CI 1.7-2.7) in 2006, which was not statistically significant P>0.05. Increase in type 1 cancer is most marked in age groups 60-69 years (P<0.001) and 70-79 years (P<0.001) and distributed equally among socioeconomic quintiles. While outcome for type 1 cancer has improved, 1-year survival in type 2 cancer is unchanged from 73.1% in 1994 to 74.3%, P=0.089 and 5-year survival decreased from 55.1% to 40.9%, P=0.001.

Conclusion: Increased incidence in endometrial cancer is confined to type 1 cancers, seen most in the 60-79 age groups and across all socioeconomic quintiles. Survival in type 2 cancer has decreased significantly. Urgent research is needed to investigate prevention strategies in type 1 and improve therapy in type 2 cancers.

Mentions:
The overall distribution of our cases among the socioeconomic quintiles was roughly similar with the exception of the smaller proportion of cases overall that were diagnosed in the most affluent quintile (Table 2; quintiles 1–5 with 1 being most deprived and 5 being least deprived). Analysis of the increase in type 1 endometrial cancer by socioeconomic distribution revealed that this increase in incidence rates was evenly distributed among all socioeconomic quintiles. There was a strong relationship between the rates of increase in groups 1 and 2 vs groups 4 and 5, r=0.74, P=0.004. Figure 2 represents an analysis of type 1 cancer incidence comparing groups 1 and 2 with groups 4 and 5. When analysing the distribution of all cases by age, the largest proportion of cases fell in the 60–69 age group, which accounted for 31% of all cases. The 0–59 group was the second largest, although in over 99% of cases, the age at diagnosis was in the 30–59 age group (Table 3). To investigate the impact of increased life expectancy on type 1 cancer we analysed the ASRs in age groups 0–59, 60–69, 70–79, and over 80 years. An increase in type 1 endometrial cancer was seen in age groups, 0–59 years: r=0.707, P=0.007; 60–69 years: r=0.861, P<0.001; and 70–79 years: r=0.838, P<0.001 over the study period, while the age standardised incidence in the over 80 years remained static; 80+ years: r=0.24, P=0.418 (Figure 3).

Mentions:
The overall distribution of our cases among the socioeconomic quintiles was roughly similar with the exception of the smaller proportion of cases overall that were diagnosed in the most affluent quintile (Table 2; quintiles 1–5 with 1 being most deprived and 5 being least deprived). Analysis of the increase in type 1 endometrial cancer by socioeconomic distribution revealed that this increase in incidence rates was evenly distributed among all socioeconomic quintiles. There was a strong relationship between the rates of increase in groups 1 and 2 vs groups 4 and 5, r=0.74, P=0.004. Figure 2 represents an analysis of type 1 cancer incidence comparing groups 1 and 2 with groups 4 and 5. When analysing the distribution of all cases by age, the largest proportion of cases fell in the 60–69 age group, which accounted for 31% of all cases. The 0–59 group was the second largest, although in over 99% of cases, the age at diagnosis was in the 30–59 age group (Table 3). To investigate the impact of increased life expectancy on type 1 cancer we analysed the ASRs in age groups 0–59, 60–69, 70–79, and over 80 years. An increase in type 1 endometrial cancer was seen in age groups, 0–59 years: r=0.707, P=0.007; 60–69 years: r=0.861, P<0.001; and 70–79 years: r=0.838, P<0.001 over the study period, while the age standardised incidence in the over 80 years remained static; 80+ years: r=0.24, P=0.418 (Figure 3).

Bottom Line:
This study investigates the observed incidence trends of the two types, the age, stage, and socioeconomic distribution of this increase and survival outcome.While outcome for type 1 cancer has improved, 1-year survival in type 2 cancer is unchanged from 73.1% in 1994 to 74.3%, P=0.089 and 5-year survival decreased from 55.1% to 40.9%, P=0.001.Urgent research is needed to investigate prevention strategies in type 1 and improve therapy in type 2 cancers.

Background: Endometrial cancer is the most common gynaecological cancer in the western world, the incidence increasing in the United Kingdom by over 40% since 1993. Two types of endometrial cancer exist - oestrogen-dependent type 1 with good prognosis and non-oestrogen-dependent type 2 with poor prognosis. The histopathological distribution of the increase in endometrial cancer is unknown. This study investigates the observed incidence trends of the two types, the age, stage, and socioeconomic distribution of this increase and survival outcome.

Methods: Data were analysed from 6867 women with endometrial cancer registered between 1994 and 2006, at a UK population-based cancer registry.

Results: Increased endometrial cancer incidence is confined to type 1 cancers with a significant increase in age standardised incidence rate (ASR) from 12.0 per 100,000 (confidence interval (CI) 10.7-13.2) in 1994 to 16.3 per 100,000 (CI 14.9-17.7), P<0.001 in 2006, while ASR of type 2 cancer changed from 2.5 per 100,000 (CI 2.0-3.1) in 1994 to 2.2 per 100,000 (CI 1.7-2.7) in 2006, which was not statistically significant P>0.05. Increase in type 1 cancer is most marked in age groups 60-69 years (P<0.001) and 70-79 years (P<0.001) and distributed equally among socioeconomic quintiles. While outcome for type 1 cancer has improved, 1-year survival in type 2 cancer is unchanged from 73.1% in 1994 to 74.3%, P=0.089 and 5-year survival decreased from 55.1% to 40.9%, P=0.001.

Conclusion: Increased incidence in endometrial cancer is confined to type 1 cancers, seen most in the 60-79 age groups and across all socioeconomic quintiles. Survival in type 2 cancer has decreased significantly. Urgent research is needed to investigate prevention strategies in type 1 and improve therapy in type 2 cancers.